The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
Internal combustion engines draw air into an intake manifold through an inlet system that may be regulated by a throttle. The air in the intake manifold may be distributed to a plurality of cylinders through a plurality of intake valves, respectively, and combined with fuel to create an air/fuel (A/F) mixture. The A/F mixture may be combusted within the cylinders to drive pistons that rotatably turn a crankshaft generating drive torque. Exhaust gas resulting from combustion may be expelled from the cylinders through a plurality of exhaust valves, respectively, and into an exhaust manifold.
The intake and exhaust valves may be actuated by one or more camshafts. Alternatively, however, the intake and exhaust valves may be actuated using electrically controlled hydraulic actuators (“electro-hydraulic” control). The electro-hydraulic control of intake and exhaust valves of an engine may be referred to as electro-hydraulic valve actuation (EHVA). Therefore, an engine that incorporates EHVA may not include camshafts (i.e., a cam-less engine). For example, EHVA systems may selectively actuate (i.e., open) intake and exhaust valves by controlling hydraulic pressure (e.g., oil pressure).